Open Sprung mattress are the traditional lower cost construction type.
All springs are fixed together, lengthways and width ways.
Because the springs are larger open sprung mattresses tends to have less than half of the springs of a pocket sprung mattress.
For example an open spring (or Bonnell spring) is 3” (75mm) in diameter where pocket sprungs come in different sizes but are usually only around 1” (25mm) in diameter.
